Websocket

The embedded Websocket server provides push notifications for applications which require real-time feedback from devices like light switches and motion sensors.

since version 2.04.40

Websocket port

By default the Websocket server is started on a proxy friendly port which, depending on the system, is either 443, 8088, 8088, 20877 or any other unused random port. The port can also be specified on commandline with the --ws-port=<port> switch.

The port in use can be queried via configuration REST-API endpoint.

Response

{
    "websocketport": 8088,
    ...
}

Possible errors

403 Forbidden

503 Service Unavailable

Open connection

How to establish a connection to an websocket server depends on the underlying programming environment.

Javascript example

The following example demonstrates how to establish a connection with Javascript in a browser or NodeJS implementation.

var host = '192.168.1.202';
var port = 8088;

var ws = new WebSocket('ws://' + host + ':' + port);

ws.onmessage = function(msg) {
    console.log( JSON.parse(msg.data) );
}

Message format

Messages received over a Websocket connection contain data in JSON format.

Button event example

{
    "t": "event",
    "e": "changed",
    "r": "sensors",
    "id": "12",
    "state": { "buttonevent": 2002 }
}

When a button of a switch is pressed the event will fire immediatly. For switches which support hold and long press/release multiply events will fire, like 1001 (hold) and 1003 (release).

Sensor presence signal example

{
    "t": "event",
    "e": "changed",
    "r": "sensors",
    "id": "7",
    "state": { "presence": true }
}

Message fields